Liquid coating compositions



Patented Aug. 25, 1936 UNITED STATES PATENT OFFIQE Wingfoot Corporation,

Wilmington, Del., a

corporation of Delaware No Drawing. Application September 18, 1934,Serial No. 744,558

25 Claims.

This invention relates to improvements in liquid coating compositionsmade from condensation derivatives of rubber. It includes the new liduidcoating compositions, methods of preparing them and their application.

The liquid coating compositions of this invention may be made fromcondensation derivatives of rubber the preparation of which is describedin my prior applications. Serial Number 635,686, filed October 1, 1932,and Serial Number 701,376 filed December 7, 1933, of which thisapplication is in part a continuation. The condensation derivatives maybe essentially hydrocarbons or they may contain a small amount of one ormore other elements such as a halogen, etc.

The rubber condensation derivative may, for example, be prepared bydissolving rubber, preferably milled pale crepe rubber, in benzene orother rubber solvent to give a concentration approximating 10% rubber byweight. This cement is heated in a steam-jacketed, or preferably awater-jacketed Day mixer or similar apparatus. If the halide of anamphoteric metal, such as tin tetrachloride is used as the conversionagent the cement is boiled until a cement of reduced viscosity isobtained before the conversion agent is added. If hydrochloric acid isused with such a halide, or a compound such as chlorostannic acid isemployed, such preboiling of the cement is unnecessary. Approximately10% by weight of a conversion reagent, such as tin tetrachloride orhydrated chlorostannic acid, H2S1iC1s.6H2O, may be add-ed to effect thecondensation. This may be prepared by saturating tin tetrachloride withhydrogen chloride at zero degrees Centigrade. If the halide of anotheramphoteric metal is employed the same relative amount of hydrochloricacid may be used although more or less hydrochloric acid may be employedand the halogen content of the rubber derivative varied. Thecondensation may be effected by heating and agitating the mixture of therubber cement and conversion agent for a period of from 2 to 6 hours attemperatures between and 0., but at any event near the boiling point ofthe solvent.

The temperature at which the conversion of the rubber to the rubberderivative is effected and other factors will control the nature of therubber derivative produced. A product of higher or lower softening pointmay be obtained. After the reaction has been carried to the desiredpoint the reaction product may be freed from water-soluble impurities byquenching in a large volume of Water, that is by pouring it into watermaintained in a state of agitation. If only a small amount of water isused an emulsion will be obtained in which the water forms thediscontinuous phase and the solution in the organic solvent forms thecontinuous phase. If, on the other hand, a large volume of water isemployed, 5 the water will form the continuous phase and the solution inthe organic solvent will form the discontinuous phase. By quenching ismeant the use of sufiicient water to form the latter type of emulsionand sufficient agitation is employed 10 to produce a more or less fineemulsion. Heat at a temperature in the neighborhood of the boiling pointof the solvent is then applied, whereupon the solvent evaporates leavingthe rubber derivative as a finely divided precipitate. 5 Illustrative ofthis step 25 pounds of reacted cement originally containing 10% rubberare placed in a container holding 28 gallons of cold water agitated bysuitable means, such as a propeller blade, rotating at the rate ofapproxi- 20 mately 240 R. P.lVI. The container is then closed and steamintroduced at such a rate that the vapor temperature in an ordinarycolumn extending from the container to a condenser reaches F. in 10minutes. During the next 10 min- 25 utes the temperature is allowed torise to F., during which interval the majority of the solvent distillsoil. The temperature is then increased to ZOO-210 F. in the next fiveminutes and permitted to remain there for another five minutes, duringwhich practically all of the re mainder of the solvent distills off. Bysuch removal of the solvent the rubber derivative is precipitated in afinely divided sand-like form and may then be centrifuged, washed withwater and dried in a vacuum oven. By varying the rate of distillationand agitation the size of the particles of the rubber derivative may becontrolled. Sand-like particles will in general be satisfactory. Incarrying out the reaction it is desirable to maintain reducingconditions or to at least exclude the air as much as possible. Forexample, in the reaction vessel in which the rubber cement is treatedwith the conversion agent it will ordinarily be desirable tosubstantially fill the vessel with the rubber cement and reagent andthus reduce to a minimum the amount of air in the vessel. It isdesirable to remove the reacted cement from the reactor as soon aspossible after the reaction has been completed. In transferring thereacted cement from the reaction vessel to the quenching tank, contactwith air is to be prevented so far as possible. A reducing agent, suchas sodium sulfite or hydroquinone, etc. is advantageously added to thequenching water so 55 as to prevent oxidation by air dissolved in thequenching water and also prevent oxidation in the subsequent heatingstep in which the solvent is volatilized. The quenching operation shouldnot be unduly extended. In this way the rubber derivative may beobtained in a substantially unoxidized condition free from water-solubleimpurities and by using construction materials not attacked by theconversion product a substantially completely colorless product isproduced. By this procedure the rubber derivative is produced in afinely divided form in which a large surface is exposed to the oxidizingaction of the air. If this material is to be stored, an air-tightcontainer is advantageously used, or preferably the material is storedin an inert atmosphere. The material is advantageously milled soon afterproduction to produce an agglomerated mass in which much less surface isexposed to the atmosphere than in the finely divided state in which thematerial is prepared. Although all of these precautions areadvantageously observed, a substantially unoxidized product for use incoating compositions may be obtained even though some slight oxidationoccurs.

The rubber derivative is preferably produced from rubber by the reactionof chlorostannic acid.

A rubber cement is prepared by dissolving in benzene 10% by weight ofpale crepe rubber which has been plasticized to a condition such that acubic inch heated sample thereof when placed on a fiat plate beneath afiat 10 kilogram weight for 2 minutes in a cabinet heated to atemperature of 70 C. is flattened out to a thickness slightly less thaninch. This corresponds to a plasticity of about 300 as measured by aWilliams plastometer.

Three hundred and fifty gallons of the cement so prepared is treatedwith 10% of chlorostannic acid in a Day mixer equipped with an agitatorand reflux condenser and heated and agitated for a-period of about 3hours at between 65 and 80 C. Samples are then taken every few minutesand the viscosities determined by suitable means. The reaction iscontinued until cement of a predetermined viscosity is obtained. In'general a reaction period of about 6 hours will be required althoughthis varies from batch to batch.

Any viscosity instrument may be used in making the determination. Onesatisfactory instrument is a Gardner mobilometer which measures theviscosity of a sample in terms of the time in minutes required for aplunger of known weight and area to fall a known distance in a cylinderof known volume containing the test sample, the clearance between theplunger and the wall of the cylinder being known. All readings in suchan instrument are taken at a standard temperature, a temperature of 25C. being selected for the determinations recorded herein. Themobilometer used had the following dimensions:

Thicknessof plunger 0.066 inches Diameter of plunger disc 1.502 inchesDiameter of plunger shaft 0.248 inches Inside diameter of cylindercontaining test sample 1.535 inches Height of cylinder 9.0 inches Lengthof plunger shaft 20.0 inches Distance between the two marks on plungershaft 7.484 inches Total weight of shaft, top weight and disc 68.6 gramsWhen the viscosity of the cement reaches a point about .05 to .07 minuteabove the desired final viscosity, which is generally 0.30:0.10 minute,preferably 0.28 to .32 minute, the reaction is preferably stopped by theaddition of grams of sodium hydroxide (dissolved in water) per pound ofchlorostannic acid used in the reaction, or by the addition of one pintof Water per pound of chlorostannic acid used. The batch is then cooledand filtered and quenched 'in water containing, for example ounce ofsodium sulfite per gallon. The benzene is removed from the resultingemulsion by steam distillation as described.

The preferred product made by this process has a softening point betweenand 65 C. and liquefies at a temperature above 150 C. When milled it issoluble (completely dispersed) in aromatic solvents, such as benzene,toluene, coaltar naphtha, etc., turpentine and turpentine substitutesand petroleum distillates, except very low boiling petroleum ether. Itis insoluble in alcohol, acetone and the commonly used lacquer solvents.It is no darker than light amber in color in granular form and issubstantially clear and colorless in films 25 to 30 microns inthickness. The chlorine content is about 1.0 to 1.2%. When applied as alacquer, by brushing or spraying, it dries rapidly to give an oxidizedfilm.

In general, coating compositions made from this condensation derivativeof rubber show remarkable resistance to acids, alkalis and corrosivechemicals. They also very effectively withstand moisture penetration asproved by salt water spray and immersion tests on both iron and steelpanels. Films from enamels adhere extremely well to metals, concrete,glass and wood.

The condensation derivative is tasteless, odorless and non-toxic and hasexcellent electrical properties. Its base color is light enough so thatall manner of bright-colored enamels can be readily developed. The filmwhich is secured is hard and fiexible and exhibits remarkable adhesionto the surface to which it is applied. The coating compositions may beapplied by brushing. spraying or dipping.

The viscosity of the solution depends upon the solvent employed.Turpentine solutions are the most viscous; those using petroleumsolvents are intermediate, with coal-tar naphtha giving the leastviscosity. The brushing resistance of these solutions is higher than formost linseed oil paints. At the same time, the covering capacity is some75% greater. Generally speaking, a 30% solution in mineral spirits canbe brushed; but this should be thinned to a concentration of 25 or 20%for spraying.

Coating compositions made with low boiling solvents quickly set to thetouch and gradually oxidize to form hard, glossy but flexible films.This hardening effect is accelerated by exposure to light; by baking;and by the use of metallic soap driers. Acidic pigments such as titaniumdioxide, iron oxide, and chromium-oxide also hasten the hardeningprocess, in contrast to the well-known efiect in linseed oil paints. Ifit is not carried too far, this drying effect improves the efiiciency ofthe coating for all sorts of difficult service, such as resistance toscraping and abrasive wear and the ability to withstand the solventeffect of oil and gasoline.

Films made from the condensation derivative dissolved in mineral spiritscan be rendered impervious to their own solvent by baking. For airdrying the same resultcan be'obtained by the judicious use of milddrying agents, such as manganese or lead-manganese driers, or by theincorporation of titanium dioxide.

The following remarks apply to plasticizers which may be employed inthese coating compositions.

Ethyl abietata-Compatible up to 30 parts per 100 of the condensationderivative. Has a tendency to become brittle on ageing.

Butyl stearate.--Compatible up to 30 parts per 100 of the condensationderivative. Gives flexible films with good adhesion. Shows a tendency tosoften on ageing.

Castor Oil-Limit of compatibility less than 10 parts per 100 of thecondensation derivative.

Santolite (A plasticizer, probably an aryl phosphate, manufactured byResinous Products and Chemical Company of Philadelphia).Limit ofcompatibility less than 10 parts per 100 of the condensation derivative.

Paraplezr (A plasticizer manufactured by Resinous Products and ChemicalCompany of Philadelphia).Limit of compatibility less than 10 parts per100 of the condensation derivative.

Tri-cresyl phosphate.Highly compatible, but

when used in amounts greater than 20 parts per 100 -of the condensationderivative the films are too soft for average purposes.

Rezyl bals'ams (Modified glycerol phthalates 'made by the AmericanCyanamid Company) 'No. 33 is essentially incompatible, the limit beingless than 1%. No. 53 is compatible up to 15 parts per 100 of thecondensation derivative. It is an effective softener and gives toughfilms which age very well and are not affected by exposure toultraviolet light for 100 hrs. It does not however, lend itself well tobaked finishes because it does not prevent the film from becomingbrittle under these conditions.

Chlorinated diphenyZs.-Aroclors #1254, #1262, and #e465 are quitecompatible, the limits being above 30 parts per 100 of the condensationderivative. They have a tendency to cause yellowing when exposed toultraviolet light or direct sunlight. Films plasticized with them do notbecome brittle on baking, but they also do not air-dry entirely tackfree. No. 4465 gives the toughest films.

Paracoumarone-z'ndene resins.-Materials of this type, such as the Cumarand Heville resins are highly compatible. They can be used in either airdrying or baking finishes, especially when acid and alkali resistanceare required.

Partition-Compatible up to about parts per 100 parts of the condensationderivative. This is an effective softener and when used in smalleramounts it gives very tough films. It can be used in either air-dryingor baking finishes.

The above compatibility limits are affected by the addition of driersand pigments, and are to a certain extent dependent upon the solventemployed. They are, therefore, not absolute values.

Very satisfactory results have been obtained, especially in bakingprimers and enamels, by modifying the condensation derivative withdrying oils. The following suggestions are offered in this connection.

Raw Chinawood oiZ.Compatible up to about 20 parts per 100 of thecondensation derivative.

derivative without reducing the gloss if the material is bakedimmediately after application. If gloss is immaterial, or if a flatfinish is desired, the oil content can be increased to above 50 partsper 100 of the condensation derivative. The addition of metallic soapdriers-will frequently increase the rate of drying of the oil andcondensation derivative -sufliciently to prevent the separation of theoil and its migration to the surface, and thus result in a glossyfinish, when without driers the finish would air dry or bake out fiat.For this purpose the manganese and lea-d manganese driers have given thebest results.

Heat treated Chinawood oil is somewhat more compatible than the raw oil,but the mechanical properties of the film are poorer. However, when thedegree of oil modification is to exceed 5% on the weight of thecondensation derivative and the finish is to be baked out in anopen-flame gasfired oven, heat-treated oil must be used to preventwrinkling.

Linseed oil.-In general, a boiled linseed oil containing lead manganesedrier (about 0.2% metal) and having a viscosity between tubes A and B(Gardner-Holdt) has been found to give Condensation derivative 100Titanium dioxide 192 Zinc oxide 48 Boiled linseed oil 200 Turpentine2'75 The limit of compatibility of this oil varies from 100% to 300% onthe condensation derivative, depending upon the quantity and type ofpigments used in the formulation. The use of this oil is recommended asa modifying agent in enamels for use on wood. In combination withChinawood oil it has given very good results in baking primers andenamels, of which the following are examples:

Red baking primer (Rustinhibitive) Condensation derivative 100 Red ironoxide 50 Zinc chromate 50 Asbestine, silica, or other inert material 75Raw Chinawood oil 50 Boiled linseed oil 50 V. M. & P. naphtha 400 Bakingschedule: minutes at 300 F.

The

Red baking enamel (Rust inhibitive) Condensation derivative 100-- Rediron oxide -Q.

Zinc chromate 60 Raw Chinawood oil 35 Boiled linseed oil 50 20%solutionPb-Mn Soligen drier 15 v. M. a P. naphtha 300 Bakingschedulez-20 minutes at 300 F.

It should be noted that, while modification with drying oils is in manycases highly desirable, these oils reduce the resistance of thecondensation derivative to moisture and corrosive chemicals and'shouldtherefore not be employed when maximum resistance is required.

To serve as typical illustrations of coating compositions suitable forcommercial use, the formulations for a number of coatings are listedbelow. These tabulations give the composition on the basis of 100 partsof the condensation derivative and in pounds per gallon. The manner ofpreparation from pre-formed bases is also indicated. These bases shouldbe used according to weight in order to secure the composition which theparticular formula demands. Each base consists of the condensationderivative into which a certain amount of pigment or inert matter hasbeen incorporated by milling on a rubber mill. Formulae for preparingthe various bases are given after the formulae for the coatingcompositions. Additional pigment or inert material may be added to abase by milling. In preparing a coating composition from thecondensation derivative or a prepared base, the dry ingredients may allbe milled into a homogeneous mass and this mass may then be readilydissolved in the vehicle to form the coating composition, withoutgrinding on a paint mill (except in a few cases such as noted in thefollowing formulae where grinding on a paint mill is desirable).

Milling the condensation derivative produces a more uniform and morereadily soluble product probably due to the fact that the surface of acondensation derivative prepared as described is oxidized so that eachparticle of the derivative is enclosed in a somewhat oxidized layer.This oxidized layer is broken down by milling and the material is thuspeptized so that it goes into solution readily. The condensation productshould therefore be milled before using in a coating composition eventhough no pigment or filler is milled into it. Directions forcompounding various bases mentioned in the following formulae are givenfollowing the formulae for the coating compositions.

Formula 1Blaclc-For exterior and interior use on iron and steelCharacterlstics.ColorBlack. High gloss. Becomes gasoline resistant afterexposure to direct sunlight for several weeks. Chalks slightly onexposure to weather, but can be polished to a high gloss. Resistschemical action as well as Formula 2 but is not as hard. Very goodresistance to abrasion.

Application-For brush application, thinning is not required. For sprayapplication, the material should be thinned percent with mineralspirits. Sets to touch in about one hour, but requires several days todry hard. Two or three coats should be applied with a minimum amount ofbrushing, allowing two hours between coats. Baking for 30 to 45 minutesat 200 degrees F. improves gloss and adhesion, and increases 4 gloss.

Formula 2--Acid and alkali resistant black Characteristics-Color black.Medium-low Resists hydrochloric acid, nitric acid, so dium and potassiumhydroxides of any concentration. Resists 50% sulphuric acid, but isquickly attacked by the concentrated acid. Very good resistance to saltspray and corrosive chemicals in general. Will not resist gasoline andoil. For interior and exterior use.

Application.-For brush application, thinning is not required. Forspraying, material should be thinned 10 to 20 percent with mineralspirits.

This material sets to touch in about 1 hour, but requires about 48 hoursto dry hard. Two or three coats should be applied with a minimum amountof brushing, allowing two hours between coats. Films should be allowedto dry five days before using subjected to corrosion tests. May beforce-dried in 1 to 2 hours at 140 degrees F.

Unlike the majority of bases, the carbon blackchina clay Base N fromwhich this paint is made does not disperse readily in the solvent, and apaint mill should be employed to obtain maximum smoothness.

Formula 3--White acid and alkali resistant enamel Characteristics.-Thisproduct has been formulated to be used in the interior of caustic tankcars. A practical test which has been in service for several monthsindicates the outstanding superiority of the material for this purpose.A modification of Formula 3 contains toluol as a solvent instead ofmineral spirits.

Application-The car should first be thoroughly cleaned by sandblasting,after which the seams are caulked, and all seams and rivets carefullycovered with the composition applied with a brush. Four coats are thenapplied over the entire inner surface of the car. If applied byspraying, equal parts of Formula 3 and the modification using toluol asa solvent are employed, thinned as necessary with mineral spirits(approximately pint per gallon) depending upon the type of spray gun.

These four coats are applied as rapidly as the material dries to touch.Then, after the fourth coat has been applied, a blower is inserted inthe end manhole of the car so that 'a good volume of air is forcedthrough the car. Care should be exercised, however, to see that the airstream does not impinge directly against the surface at any point. Thiswill cause too rapid drying, and may result in lifting or alligatoring.When the air is turned on, steam is run through the coils, bringing thetemperature up to approximately 140 degrees F. As soon as thistemperature is reached the heat is turned off and the car is kept atabout this temperature for a period of about twelve hours under draft,or until all the odor of solvent Parts by weight Pounds Material pergallon Condensation derivative 100 China cl Raw tung oil. Mineralspirits Condensation derivitive...

Raw tung oil..- Mineral spirits Formula 4--Green enamelCharacteristics.This material was formulated for use as a coating forplating room equipment.

Application-For brush application, thinning is not required. For sprayapplication, thin 10 to 20 percent with mineral spirits.

Sets to touch in about one hour, but requires about 48 hours to dryhard; two or three coats should be applied with a minimum of brushing,

allowing two hours between coats. Films should be allowed to dry fivedays before being subjected to corrosion tests.

Pounds per gallon Parts by Material Weight Condensation derivative;Titanium dioxide. Chrome green (oxide) Superfloss silica,

Raw tung oil 5 09 Mineral spirits From bases Condensation derivativeBase A Raw tung 0 Mineral spirits Formula D0ue gray enamel Formula 6-Redair drying metal enamel This material was formulated as an exteriorpaint for alkali tank cars. It is very resistant to alkalies, and tooccasional spillage of acids. This material is of proper consistency forspray application. If thinning becomes necessary use mineral spirits,solvent naphtha, or toluol. Apply one mist coat, air-dry five minutes,and apply one wet coat. The coating sets to'touch in one hour and drieshard in 24 hours. It can be force-dried for 15 minutes at 200 degreesFahrenheit.

Parts by Pounds per Material weight gallon Condensation derivative 100l. 56 Indian red oxide 150 2. 33 Raw tung oil 25 39 Mineral spirits 3004. 67

From bases Base E 250 3. 89 Raw tung oil 25 39 Mineral spirits 300 4. 67

Formula ?-Aluminum--For interior or exterior use on iron and steelCharacteristics.--Lustre improves on exposure to weather. Very hard anddoes not collect as much dust and dirt as ordinary aluminum paints.Excellent resistance to salt spray and alternate salt water immersionand weather exposure.

Applicati9n1 -For brush application thinning is not required. Forspraying, material should be thinned by diluting the vehicle 10% withmineral spirits before adding the aluminum powder.

This material sets to touch in about one hour and can be recoated in 4hours. Dries hard in 24 hours, Can be baked 5 minutes at 300 degrees F.or minutes at 200 degrees F. to produce a very hard finish. In makingaluminum paint the powder is added to the vehicle just prior to using,in order to preserve its leafing qualities. This paint, therefore, isnot formulated from a base, but is made up from the condensationderivative and solvents, and later powder, as folows:

- Parts by Pounds per Mammal weight gallon Condensation derivative100 1. 46 Turpentine 200 2. 91 Mineral spirits 200 2. 91

To this vehicle, aluminum powder, preferably 1.44 pounds per gallon, isadded immediately before use.

Formula 8-WhiteF0r iron and steel Characteristics.--Color-white. Highgloss. Becomes gasoline resistant in two to three days if exposed tolight. Not recommended for outdoor w Parts by Pounds per Mammal weightgallon Condensation derivative 100 l. 61 Titanium dioxide 150 2. 42 Zincoxide 25 40 Raw tung oil.. 5 08 Mineral spirits 300 4. 85

- Parts by Paunds Mammal weight per gallon From bases Condensationderivative 8. 5 14 ase 230. 8 3. 71 Base C. 35. 7 58 Raw tung o1 5. O 08Mineral spirits 300.0 4.

Formula 9-Brown air drying enamel Formula 10Red lead primerCharacteristics.-Color-red. Good gloss; if this is objectionable it canbe reduced by incorporating inerts such as whiting or diatomaeceoussilica. Excellent resistance to salt spray and combination of salt waterimmersion and weather exposure (alternate immersion and weather exposuretests). Fades on exposure to sunlight but does not chalk or check.

Application.-For brush application, thinning is not required. Forspraying, this material should be thinned 10 percent with mineralspirits.

This primer sets to touch in 1 to 1% hours depending on temperature andhumidity. When applied indoors at a temperature of 73 degrees Fahrenheitthe solvent completely leaves the film in 16 hours. Oxidation then takesplace and the film increases in weight for '7 days.

If the finish coat is sprayed on it can be applied over this primer in24 hours, but if applied by brushing the primer should dry at least twodays under average conditions. In cases where this drying time isprohibitive finish coats should be applied as soon as the primer hasdried to touch. This material should be allowed to dry indoors for atleast five days before being subjected to salt spray or other corrosiontests.

Formula 11-Chromate primer Characteristics.-To be used on iron, steel,and non-ferrous alloys. Color-green. Medium gloss. Excellent resistanceto moisture and salt spray.

Especially recommended as a primer for nonferrous alloys (dowmetal,duralumin, aluminum, zinc, etc.).

Application-For brush application thinning is not required. When thepaint is to be sprayed, it should be thinned 10 percent with mineralspirits. Finish coats should be applied Within one hour after thisprimer has set to touch. If this cannot be done a drying period of 24hours should be allowed before applying a finish by spraying, and 48hours by brushing. This is to eliminate any possible tendency towardlifting.

Parts by Pounds Mammal weight per gallon Condensation derivative 1.58Z1110 chromate 2. 36 Mineral spirits 300 4. 73 Formula 1 13.25 21 Frombases Base F.. 250 3. 94 300 4. 73

Formula 1 13.25 21 Formula 12-Recl baking primer-for iron and steelCharacteristics.-Color brick red. Slight gloss before baking; semi-flatafter baking. Very good flexibility and adhesion to metal. Veryresistant to salt spray.

Applicati0n.For brush application, thinning is not required. Forspraying, paint should be thinned 10 to 15 percent with mineral spirits.

This material dries very slowly and must be baked. It bakes quite hardin 20 minutes at 300 degrees Fahrenheit, but this can be increased totwo hours without affecting the flexibility or adhesion.

. Parts by Pounds per Material Weight gallon Condensation derivative 100l. 17 Red iron oxide 35. 8 .42 Asbestine. 100 1. 17 Blane fixe 100 1. 17Raw tung oil 50 58 Mineral spirits 400 4. 66

. 70 l. 68 l. 55 58 Mineral spirits 400. 0 4. 66

Formula Ill-Reel baking primerfor iron and steelCharacteristics.Colordark brick red. Semiflat after baking. Excellentresistance to salt spray. Especially designed for automotive work.

Application-For spray application only. Does not require thinning. Sprayone heavy coat, air dry not more than 15 minutes, then bake 45 minutesat 300 degrees F. for use under air drying finishes, or 30 minutes at300 degrees F. for use under baking finishes.

For best results an electric or steam heated oven should be used, as gasfired ovens frequently cause wrinkling.

Parts by Pounds per Mammal weight gallon 875 875 1. l7 23 525 525 .42Mineral spirits 4. 21

In the case of the latter formula, the superfioss silica is added inpart as such rather than entirely as Base H to produce a fiat finish.

Formula. 14--Yellow baking primer Characteristics. --This primer isemployed where a lighter colored material than Formula 13 dark redprimer is required. Has excellent resistance to salt spray and numeroustests have shown it to be highly resistant to humidity.

Application-For spraying only. Does not require thinning. Spray one mistcoat, air-dry five minutes, then spray one wet coat and bake 30-45minutes at 300 degrees F.

- Parts by Pounds per Material weight gallon Condensation derivative 1001.07 Zinc chromate 50 .535

Titanium dioxide..- 31 .33 Yellow iron oxide 50 .535

Superfioss silica 63 68 Raw tung oil..- 50 .535 Boiled linseed o 50 .535

Mineral spirits. 400 4. 30

From bases Base A- 48 .51

Base F.. 83 89 Base (2.. 83 89 Base H 57 .61

Superiloss silica- 23 25 Raw tung oil 50 535 Boiled linseed 0 50 535Mineral spirits 400 4.

The 23 parts of superfioss added as such to the latter formulation, isincorporated in this way rather than entirely as Base H to produce aflat finish.

Formula 15--Blac7c baking primer Satin finish.

minutes, spray one wet coat, air-dry five minutes and bake for 40minutes at 300 degrees F.

- Parts by Pounds per Material weight gallon Condensation derivative-100 84 Black iron oxide 50 .42 Zinc chromate. 50 42 Superfloss silica-77 65 200 l. 70 50 .42 50 .42 300 2. 54 100 From Bases Condensationderivative 4 Black iron oxide base 83. 3 .70 Base F 83. 3 .70 SuperflossBase H 110.0 .93 Formula l 200.0 1. 70 Raw tung oil 50. 0 42 Boiledlinseed oil 50. 0 .42 Mineral Spll'lllS-- 300. 0 2. 54 Tolu 100. 0 84Concrete coatings made from the condensation derivative are outstandingbecause of their good adhesion, resistance to moisture penetration, andability to withstand the effect of alkalies, both from the concrete andfrom alkaline cleansing agents. Their abrasion resistance is excellent,and these coatings ofier a means of solving the problem of asatisfactory concrete fioor covering. These finishes are also adaptableto walls, either plaster, concrete, or masonry. Formulae 16 to 20. aredesigned particularly for such use. In applying these compositions to afloor, for example, the floor must be clean and free from grease.Ordinary washing with gasoline does not sufiiciently remove the grease,but merely drives it into the pores of the concrete where the paintshould adhere. Therefore, it is suggested that the floor be cleaned byone of the following methods:

1. A cleaning fluid made by using 1 /2 ounces of tri-sodium phosphate(Oakite* and 1 ounces of soap chips per gallon of water).

2. By using Wyandotte Cleaner #3 as recommended by the manufacturer.(This can be purchased from any reputable paint supply house.)

The fioor should then be thoroughly cleaned and rinsed with clear water.In addition to this precaution, where especially greasy spots have been,or where the cement is glassy smooth, it is recommended that theseplaces be etched with a 10% solution of muriatic acid. This etching iscarried out by pouring the acid of the right concentration on the fioorand allowing it to remain until it ceases to effervesce. The acid isthen washed free and the floor allowed to dry. It is then ready forapplication of the first coat of paint.

The first coat should be applied after being thinned at least 25% withmineral spirits. This is done in order to cut down the viscosity of thepaint and allow the first coat to thoroughly penetrate into theconcrete. Subsequent coats are then applied at intervals ofapproximately two hours or longer. Another precaution which has beenfound quite desirable is that the trailic lanes in an office, forexample, be given more than two coats of the material. This is done bypainting the lanes two or three coats before the final coat is appliedto the entire floor. It is possible to deposit only a certain thicknessof film per coat of material and if this thickness is increased the wearon the floor will be longer. These concrete paints dry totouch inapproximately one hours time and the floor can be sub- Formula18.GrayFor concrete, iron, and steel Characteristics. Color dark gray.High jected to light traffic in two: to six hours after gloss. Becomesgasoline resistant in about 4 application. However, the adhesion of thefilm days .Nt recommended for t exposiuref 5 to the concrete does notdevelop to its maximum AppZwatZ.OnFOr brush b t until a period of two tofive days has elapsed. Is not requlre.d' For Spray apphcatlol? thlspamtThis means that heavy traffic should not be put shqnd be thmned percentwlth mmeljal on the floor until the coating has reached its spirits.Sets to touch in about 1 hour and dries maximum adhesion hard in 24hours. Two coats are recommended, 10

allowing about 4 hours between coats. When Formula 16-GrayFor concrete,iron, and steel applied to concrete floors this material shouldCharacteristics.--Color-blue gray. Good be allowed to harden from fourto fi days gloss. Becomes gasoline resistant in about three fore bemgsubJected severe servlce' weeks if exposed to light. Gave very good re-15 sults on concrete floor. Not recommended for Material gg fi ifiexterior work. g g

Application-For brush application, thinning r is not required. For sprayapplication, thin 10 gaggigfg gg g ggff 93 {lg to 20 percent withmineral spirits (about one 100 1.7.2 20 pint per gallon). This materialsets to touch ;3g in about one hour and dries hard in 24 hours. 5 .00Two coats are recommended allowing at least 250 two hours between coats.On concrete floors 538.5 9.40 this material should be allowed to drythree to From bases 25 four days before being subiected to severeseivice. Base A n 121 5 212 see-- as s at it... a is Mineral spirits250.0 4.35 sttarrtiizrrii 2928 :98 538-5 Zinc oxide.. 41. 39 .70

iii I8; Formula Ill-Olive gray concrete Raw tun: oil. 5.00 .08 Mineralspirit 300.00 5.00 Characteristics-This material does not dry 49221 8mgasoline resistant. When resistance to gasoline is required paint mustbe specially formulated. From bases Withstands moisture penetration andthe effect Condensation derivative 45.0% .7 of alkalies, both from theconcrete and from 333: alkaline cleaning agents. 40 a e -ZApplication.Allow about two hours between R21? $555, E58 j coats, orjust enough time for the previous coat Mineral spirit-s 300410 ff to dryto touch. Spray application is not recom- 492,21 M0 mended on concretefloors.

Parts by weight Formula 17-Wiz2'teF0r concrete, iron and steel Formula17 630-0 Formula 1 16.3 Characteristics.-Color-white, but can be Basesolution 97'0 tinted to match any light color. High gloss. Driesgasoline resistant in 24 hours. Resistant Base P Solutlon is composed ofP by Welght to acids and alkalies. Not for outdoor exposure. ofljliase Pand 50 parts by Welght of mmeml Application.For brush application,thinning Spmts' is not required. For spraying, this material Formula20Gray-For concrete, iron and steel should be thinned 10 to 15 percentwith mineral Characteristics. C010r gray High g1 Oss t F to touch Inabout one Hour and Becomes gasoline resistant in about 4 days. Not drieshard in 24 hours. Two coats should be aprecommended for outdoorexposure. plied; the second coat about one hour after the Applicationpor brush application thinning is first Coat has Set to touchnotrequired. For spray application this paint should be thinned 10 to 15percent with mineral Material art by Priundsper spirits. Sets to touchin about 1 hour and dries gallon hard in 24 hours. Two coats arerecommended, allowing about 4 hours between coats. When gpgg geg g eg gapplied to concrete floors this material should g b jj' 1 0 be allowedto harden from four to five days bei fik' ig g gg g fore being subjectedto severe service.

505 9'58 Material fjggfi ggfi g Condensation deriv .05 BaseA 2. 00Condensation derivative 100.0 1. 755 40 Base H 2. 48 Carbon black 2. 25.040 Raw tung oil .09 Titanium dioxide. 02. 80 1. 628 Mineral spirits250 4. 30 Superfloss silica... 92. 80 1.023 Raw tung 0il 5.00 .037 5559. 58 Mineral spirits 254. 50 4. 462

The hardness, flexibility, and adhesion of baking finishes formulatedwith the condensation derivative and mixtures of drying oils, togetherwith their resistance to moisture and chemicals, ofier a promising fieldin industrial applications. Formulae 21-24 should be consideredespecially in connection with sheet metal coating, where the metal issubsequently to be drawn or pressed into shape.

Formula 21--Red brown baking enamel Characteristics.Glossy. Rustinhibitive. Does not require a primer. For spray application only.

AppZicatzon.-Spray one heavy coat, air-dry not more than five minutes,and bake 20 minutes at 300 degrees F.

. Parts by Pounds per Materials weight gallon Condensation derivative100.0 1. .Red iron oxide 75.0 v .83 Zinc ohromate 75.0 .83 62. 5 70 43.8 .49 18.7 21 Mineral spirits 375. 0 4. 17

From bases Base D 125.0 1. 39 Base F 125.0 1. 39 Boiled linseed o l 62.5.70 Raw tung oil 43.8 49 20% sol. Pb-Mn drier 18. 7 .21 Mineral spirits375.0 4.

Formula .22-Brown baking enamel Characteristics-Glossy. Passes saltspray test, but is not rust inhibitive. For spray application only.

Application.Spray one heavy coat, air-dry not more than five minutes,and bake minutes at 300 degrees F., or longer if greater hardness isdesired.

- Parts by Pounds per Matenal weight gallon Condensation derivative100.0 1.30 Yellow iron oxide 82. 5 1.08 Red iron oxide 29. 7 39 Carbonblack; 6.9 .09 10% solution lead Sohgen dr1er- 5. 0 06 10% solutionmanganese Soligen drier. 15.0 20 Boiled linseed oil 85. 0 1. 11 Raw tungoil.-." 30.0 .39 Mineral spirits 300.0 3. 90

- Frombases Condensation derivative 2. l 03 Base A 137.5 1.80 Base D.49. 5 .64 Base 13 30. 0 39 10% sol. lead Soligcn drier 5.0 .06 10% sol.manganese Soligen 15. 0 20 Boiled linseed oil 85.0 1. 11 Raw tung oil30.0 .39 Mineral spirits 300.0 3. 90

Formula 23Brown baking enamel Characteristics.Deve1oped primarily forbeer barrels. Passes salt spray test satisfactorily, but is not rustinhibitive. Spray application only.

Application.--Spray one heavy coat. Bake 45 minutes at 240 degrees F. or30 minutes at 300 degrees F.

Parts by Pounds per Material weight gallon Condensation derivative 100.0 1. 31 Brown iron oxide 87.0 1.14 Superfloss silica 22.0 29 Carbonblack. 4. 0 05 Boiled linseed o1 56.5 .74 Raw tung oil 31. 0 40 10%solution PbMn Soligen drier. 26.0 34 Mineral spirits 300. 0 3. 93

From bases Base R 174.0 2. 28 Superfioss silica* 22.0 29 Base B 17.0 .22Boiled linseed oil 56.5 74 Raw tung oil 31. 0 40 10% solution Pb-MnSoligen drier 26.0 34 Mineral spirits 300. 0 3. 93

flhe superfloss silica in this material is incorporated in a paint m1lland not as Base H (70% superfloss silica-30% condensation derivative) inorder to produce flatness.

Formula 24-Black baking metal enamel Characteristics.GloSsy. Passes saltspray test. For spray application only.

- Application.For a one-coat job, bake immediately after application for20 minutes at 300 degrees F. For a two-coat job, air-dry 10 minutesbetween coats, then bake 30 minutes at 300 degrees F.

Formula Semi-flat white maintenance paint Characteristics-Light andpastel shades may readily be made from this material by tinting. It hasshown very good resistance to water, soaps, and alkaline cleaningagents.

Application-For brush application, thinning is not required. For sprayapplication, thin 10 to 20 percent with mineral spirits. When two coatsare necessary apply the second about one hour after the first has set totouch. If this cannot be done a drying period of 24 hours should beallowed before spraying, or 48 hours before brushing on the second coat.

T Parts by Pounds per Material weig gallon Condensation derivative100 1. 58 Titanium dioxide.--" 150 2. 37 Superfloss silica.-- 25 40 ZincXld6 25 .40 Raw tung oil 08 Mineral spirits 300 4. 74

From bases Condensation derivative 8. 3 13 Base A 231. 0 3. 66Superfloss silica't- 25. 0 40 Base 0 35. 7 56 Raw tung oil- 5.0 08Mineral spirits 300. 0 4. 74

The superfioss silica in this material is incorporated in a paint milland not us Base H (70% superfloss silica 30%condensation derivative) inorder to produce flatness.

Formula 26-Gloss white maintenance paint Characteristics.-Light andpastel shades may readily be made from this material by tinting. Itshows very good resistance to water, soaps, and alkaline cleaningagents.

Application-For brush application, thinning is not required. For sprayapplication, thin 10 to 20 percent with mineral spirits. When two coatsare necessary apply the second about one hour after the first has set totouch. If this cannot be done a drying period of 24 hours should beshould be allowed before spraying, or 48 hours before brushing on thesecond coat.

- Parts by Pounds per Mammal weight gallon Condensation derivative 100l. 55 Titanium dioxide 150 2. 32 Superfloss silica. 50 77 Zinc oxide..25 39 Raw tung oi 5 08 Mineral spir 300 4. 65

From bases Condensation derivative 8.6 1. 13 ase 230. 7 3. 58 Base C-..35. 7 .55 Superiioss s ca 50. 0 77 Raw tung oil..- 5. 0 08 Mineralspirits 300.0 4. 65

The superiloss silica in this mixture, is incorporated on a paint millfor flatness, and not as a base.

Formula 28--Green air drying wood enamel allowed before spraying, or 48hours before brush- Material :23; 53 p ing on the second coat.

Condensation derivative 100 1.30 P b P d gitallillll dioxide 13(1) 5 2.arts y oun sper inc oxi e Material weight gallon Base F solution. 70. 091 Glen green solution 35.0 45 4-hour linseed oil 35. 0 45 Condensationderivative 100 1. 54 Mmeml 0 58 Titanium dioxide 150 2. 30 inc oxide...l2g g 5 18 aw tung oi Bo led linseed oil. 25 .as From bases Mme! Spmts300 62 gondgnsation derivative 246.3 $66 ase ase so u ion. From basesGlllen grleen soilution 4- our insee oi $25???.i'ffiiiiiifi: 23%?) 3:3Mineral spirits 0 58 Base 0..-. 35.7 .55 Raw tung 011-. 5. 0 .os 5 181laloiled llinseeii oi 4. 38

inera spiri s .62 l

The above mentioned solution of Base F is com- 6050 posed of 250 partsby weight of Base F and 300 Formula 27--Flat white maintenance paintCharacteristics.-Light and pastel shades may readily be made from thismaterial by tinting. It shows very good resistance to water, soaps, andalkaline cleaning agents.

AppZication.-For brush application, thinning is not required. For sprayapplication, thin 10 to 20 percent with mineral spirits. When two coatsare necessary apply the second about one hour after the first has set totouch. If this cannot be done a drying period of 24 hours mineralspirits. The Glen green solution is made up of 100 parts by weight ofcondensation derivative, 30 parts Glen green, and 225 parts mineralspirits.

Formula 29-Glossy white wood enamel Characteristics.This material isresistant to water penetration, and to the effect of soaps and alkalinecleaning agents.

AppZication.-Wood that has not been previously painted should be primedwith white lead in oil. If a second coat is necessary this must beapplied as soon as the first coat has set to touch. If this cannot bedone allow the first coat to dry 24 hours before applying the second. Ifthina052, 391 1 1 nine becomes necessary use pure spirits of turpentine.Material Egg}? $61,

Parts by Pounds per Material weight gallon g 8 M. 21. 5 41 Condensationderivative 103.3 meta] Spmts 5 46 3 8 398. 75 7. 58 5. 5 Mineral spirits250. 0 4. 19 bases Condensation derivative 1.0 .02 57115 9 ase 118. 0 2.24 Base Am- 14.5 .28 From bases Base C 2.0 .04 Condensation derivative 531; iia :5? 32: 6 g

4-hour linseed 011. 21. 5 41 4.110511551111552 35. 0 .58 Mme'fll 5Mineral spirits 250. 0 4. 19 75 7. 58

Formula 30--Glossy yellow wood enamel Characteristics and applicationsame as for Formula 29.

Parts by Pounds per 'Matenal weight gallon Condensation derivative 100.0 i. 58 Titanium dioxide 144.0 2. 27 Zinc oxide 28. 5 .45 Zinc chromate11. 0 17 Yellow iron oxide 3. 5 05 4-hour linseed oil. 31. 5 Mineralspirits 277. 5 4. 38

From bases Condensation derivative 7 use A 221. 5 3. 50 Base 0." 40. 764 Base F 18. 3 .29 Base P 1 5. 8 09 4-hour linseed oiL 31. 5 .50Mineral spirits 277. 5 4. 38

Formula ll-Glossy dark gray wood enamel Characteristics and applicationsame as for Formula 29.

Parts by Pounds per Mammal weight gallon Condensation derivative100.0 1. Titanium dioxide 87.0 1. 34 Zinc oxide 14. 5 22 Carbon black.12. 5 19 Raw tung 011... 5.0 08 4 hour linseed Ol 23. 5 36 Mineralspirits 800. O 4. 65

From bases Condensation derivative 5. 0 08 ase A 134. (J 2. 06 Base C20. 5 .32 Base B... 54. 5 .84 Raw tnng oil. 5.0 .08 4-hour linseed 0 23.5 .36 Mineral spirits 300. 0 4. 65

Formula 32-Gl0ssy dark blue wood enamel Characteristics and applicationsame as for Formula 29.

The bases referred to in the above formulae are prepared by millingtogether the ingredients specified below on a rubber mill.

Rubber cond. Base No. derivative Pigment or filler 5:5

. percent g y A 35 65% Titanium oxide 2.03 B 77 23% Carbon black. 1. 17C 30 70% XX50 zinc oxide 2. 45 D 40 Red iron oxide 1. 96 E 40 60% Indianred iron oxide..- 2.00 F 40 60% Zinc chromate 1. 78 G 30 1. 88 H 30 1.69I 50 01 y 1. 51 J 30 70% Chrome green (oxide)- 2. 38 K 75 25% Prussianblue 1. 19 L 35 Titanox C 1. 89 M 25 75% Blane fixe 2. 45 N 52. 6 15.8%Carbon black: 31.6 1.41

china clay. O 28. 5 57.2% Red lead: 14.3% Zinc 2. 79

ox e. P 40 60% Yellow iron oxide 1. 94 Q 40 60% Yellow ironoxide-light. 1. 89 R. r 50 50% Brown iron oxide 1. 72

a-Water immersion.Each of the Formulae 1 to 9 has been tested formoisture penetration and their high resistance to moisture penetrationis illustrated by the following:

1. Galvanized iron coated with Formula 1 Black has been immersed inwater continuously for one year without any efifect on the film.

2. Galvanized iron coated with Formula 10--Red lead primer has beenimmersed in water continously for 8 months without any efiect on thefilm.

3. Black iron panels coated with Formula 2A cid and alkali resistantblack have been immersed in wamr 2 months without any effect on thefilm.

4. Iron racks coated with Formula 10 Primer, Formula 1 Black and Formula16 Gray have been subjected repeatedly to the action of open steam at285 F. without any eifect.

5. Water has been boiled for 8 hours in a steel crucible coated with abaked finish. After the test the film was still in excellent condition.w

b-Salt water immersion.-Numerous coated panels were subjected to thealternate immersion test. In this test the] panels were immersed in a 5%solution of sodium chloride at night and exposed to the sun (45 facingsouth) in the daytime. Compositions containing high properties ofpigment gave the best results in this test. Several Intro-cellulose andphthalic-anhydrideglycerol lacquers, oil paints and asphalt paints werealso subjected to this test. nite corrosion after two months.

All showed defi- A panel covered with one coat of Formula 10 Primer andtwo coats of Formula 7 Aluminum were in excellent condition after fivemonths of exposure. Panels, similarly coated were immersed in Lake Eriewater at Lorain Harbor. The film was stillperfect upon removal of thepanels after six months immersion.

c-Salt swan-Several hundred panels have been tested by salt spray. Ineach case three coats of the condensation derivative were applieddirectly to sand-blasted black iron (unprimed).

Results:

1. Oil paints, except those containing large amounts of red lead, zincchrom'ate or aluminum powder, fail by blistering and corrosion in 200hours or less.

2. Nitrocellulose lacquers fail by corrosion in four to five days.

3. Phthalic-anhydride-glycerol lacquers usually do not show appreciablecorrosion in 200 hours, but they lose adhesion and become brittle.

4. Coating compositions of this invention, clear or any color, pass the200 hour salt spray test in perfect condition. Formulas 2, 10 and 12have successfully stood this test 30 to 60 days.

COMPARATIVE RATING Water Immersion-Salt water-Salt spray tests Alkalitests 4. Panels immersed in 50% sodium hydroxide for 120 days showed noeffects. Iron panels brush coated with this Formula 2 and immersed in20% and 30% sodium hydroxide showed no indication of failure after 712hours.

Comparative rating of mechanical properties One of. the characteristicproperties of the paints of this invention is the rapid dryingqualities. The following table shows the comparative drying rate ofthese and other commonly used finishes.

Drying time in air Water im- Salt-water mersion immersion salt'spmy Totouch To recoat For service Coating Compositions of Good Good Very go dCoating compositions 1 hour 24 hours 24-48 hours this invention. of thisinvention. Oil paints Fair Poor Poor Oil paint 24-36 hours 24 hours or2-5 days Nitrocellulose lacquer. Poor-Fair Poor Very poor more Blackbaked lacquer Poor Poor-Fa1r Fair-Good Nitrocellulose lacquer 515 min.minutes 24 hours Air dried clear lacquer Poor Poor-Fair Fair Black bakedlacquer .51.5 hours .5l.5 hours After baking Chlorinated rubber... GoodFair PoorFa1r Air-dried clear lacquer .5 hour 2 hours 8 hours Commercial4-hour en- Fair Poor Poor Clear varnish 6-8 hours 24 hours 2-5 daysamel. Chlorinated rubber 30 minutes 30 minutes 1 hour Commercial 4-hour1.5 hours 4hours 24 hours enamel. d-Chemical resistance tests.Allcoating compositions of this invention, both clear and pigmented, areunusually resistant to chemical attack. Formula 2 Black has beenparticularly designed for this service, however, and is recommendedwhere conditions are unusually severe. This will resist concentratedhydrochloric and nitric acids; sulphuric acid up to 50% concentrationand alkalies of any concentration. Formulae 3, 4, 5 and 9 have beendeveloped for caustic immersion, such as for the lining of caustic tankcars, and have been used with excellent results. The following testshave been conducted on iron panels coated with Formula 2.

Acid tests 1. Several drops of concentrated hydrochloric acid wereapplied and allowed to evaporate at room temperature with no effect onthe film. Iron panels, brush coated, immersed in 5%, 10%, andhydrochloric acid at room temperature, showed no indication of failureafter 718 hours.

2. Several drops of concentrated nitric acid were applied and allowed toevaporate without effect.

3. Panels immersed in 1:1 sulphuric acid for two weeks showed nofailure. Iron panels, brushed coated with this Formula 2, and immersedin 5%, 10%, 20% and 30% sulphuric acid at room temperature showed noindication of failure after 716 hours.

Coating compositions of this invention can be extensively used as aprimer and undercoating. The rapid drying quality, excellent adhesionand resistance to moisture meet the needs of a primer most successfully.No trouble has been experienced in applying any other types of paint,enamel or lacquer as finishing coats over them. For metal protectionthey have the distinct advantage of drying rapidly to form a hard filmwhich resists scraping and abrasive wear most effectively. They alsostand up much more satisfactorily under moisture and salt-sprayconditions. Their attractive appearance, resistance to alkalies, acids,oils and gasoline give them excellent properties for the original andmaintenance coats on all forms of machinery. Since limited amounts ofthem can be advantageously blended with linseed oil paints, more rapidlydrying wood paints having improved resistance to moisture can be securedat a small additional cost. On concrete and plaster they give improvedadhesion, resistance to abrasive wear, greater moisture resistance andmore rapid drying. For automotive work, they provide an excellent primerbase. The improved adhesion, more effective resistance to moisture andmore flexible film provide a hard, firm base for subsequent finishingcoats. Due to their acid and alkali resistant qualities, they providethe ideal paint for equipment for chemical plants and the like. Theywithstand caustic immersion for prolonged intervals, are recommended forcasual contact with acids, and are resistant to a great many severeconditions. Cold out and blended with oils, they give tough, adhesivefilms with high resistance to humidity which make them excellentprocessing enamels.

The preferred compound recommended for use in the above formulae is thechlorine-containing rubber condensation derivative, the preparation ofwhich is described above. Other condensation derivatives of rubber maybe used. They may be substantially halogen-free, as for example,

products made by the condensation of rubber with halides of amphotericmetals, such as tin tetrachloride, chromic. chloride, etc. Condensationderivatives which are soluble (dispersible) in the cheap petroleumdi'stillates have a distinct commercial advantage and are thereforegenerally preferred. By'employing a substantially unoxidized derivativeas herein disclosed 'a film is produced which oxidizes on exposure toair and by using a suitable vehicle a coating is produced which onexposure to the air becomes insoluble in the vehicle.

The preparation of condensation derivatives of rubber is covered in thefollowing copending applications:

Sebrell, Ser. No. 654,248, filed January 30, 1933; Kurtz, Ser. No.680,982, filed July 18, 1933; Thies 8: Lyon, Ser. No. 699,634, filedNovember 24, 1933; Sebrell, Ser. No. 718,215, filed March 30, 1934;Wright, Ser. No. 718,686, filed April 2, 1934.

I claim:

1. A coating composition which comprises (a) liquid vehicle composed insubstantial part of volatile petroleum distillate and (b) dispersedtherein a substantially unoxidized condensation derivative of rubberwhich condensation derivative of rubber (1) is substantially identicalwith the product of a process of making in which oxygen is substantiallyexcluded and contains substantially no oxidized material, (2) is readilyoxidizable to a product which is insoluble in said vehicle and (3) isdissolved and completely dispersed in saidvehicle.

2. A coating composition which comprises (a) liquid vehicle composed insubstantial part of volatile petroleum distillate and (b) dispersedtherein a substantially unoxidized condensation derivative of rubberwhich condensation derivative of rubber (1) is substantially identicalwith the product of a process of making in which oxygen is substantiallyexcluded and contains substantially no oxidized material, (2) is nodarker than light amber in color in granular form and is substantiallyclear and colorless in films 25-30 microns in thickness, (3) liquefiesat a temperature above 0., (4) is readily oxidizable to a product whichis insoluble in said vehicle and (5) is dissolved and completelydispersed in said vehicle.

3. A coating composition which comprises (a) liquid vehicle composed insubstantial part of volatile petroleum distillate and (b) dispersedtherein a substantially unoxidized condensation derivative of rubberwhich condensation derivative of rubber (1) is obtainable bydecomposition with water of a conversion product obtainable by thetreatment of rubber in solution with chlorostannic acid, (2) is nodarker than light amber in color in granular form and is substantiallyclear and colorless in films 25 to 30 microns in thickness, (3) isreadily oxidizable to a product which is insoluble in said vehicle, (4)is present in the coating composition in a state in which it issubstantially free from watersoluble impurities and (5) is dissolved andcompletely dispersed in said vehicle.

4. An article comprising wood, metal, plaster, concrete or masonrycoated with a film formed from the coating composition of claim 1.

5. An article comprising wood, metal, plaster, concrete or masonrycoated with a film formed from the coating composition of claim 2.

6. An article comprising wood, metal, plaster,

' the only readily volatile solvent therein.

8. A coating composition which comprises an acidic pigment, petrol eumdistillate and a substantially unoxidized condensation derivative ofrubber which is substantially identical with the product of a process ofmaking in which oxygen is substantially excluded and containssubstantially no oxidized material, the petroleum distillate being theonly readily volatile solvent therein.

9. The coating composition of claim 1 in which an acidic pigment ispresent to hasten the oxidation of the condensation derivative ofrubber.

10. The coating composition of claim 2 in which an acidic pigment ispresent to hasten the oxidation of the condensation derivative ofrubber.

11. The coating composition of claim 3 in which an acidic pigment ispresent to hasten the oxidation of the condensation derivative ofrubber.

12. A coating composition containing an acidic pigment, a basic pigmentand a condensation derivative of rubber which is substantiallyunoxidized.

13. A coating composition containing a substantially unoxidizedcondensation derivative of rubber, which rubber derivative is free fromwater-soluble ingredients formed in the conversion of rubber to such aderivative and is mixed into the coating composition in a statesubstantially free from colored impurities.

14. A coating composition, the liquid vehicle of which contains at least50% by Weight of petroleurn solvent and the non-volatile portion ofwhich is composed chiefly of a condensation derivative of rubber whichis substantially unoxidized.

15. A coating composition which contains in eighty parts of volatilevehicle at least twenty parts by weight of a condensation derivative ofrubber which is substantially unoxidized.

16. A coating composition which contains in eighty parts of volatilevehicle at least twenty parts by weight of a condensation derivative ofrubber which is substantially unoxidized, such vehicle being composedlargely of a petroleum solvent.

17. A coating composition which comprises a condensation derivative ofrubber sufficiently soluble in petroleum distillate to be applied in avehicle composed entirely of petroleum distillate which coatingcomposition contains sufficient acidic pigment to render a film of thecoating composition resistant to petroleum solvent after 24- hoursexposure to light.

18. The method of making a coating composition which comprisesintimately mixing a color into a condensation derivative of rubber,intimately mixing another color into a condensation derivative of rubberand dissolving the differently colored rubber derivatives in a vehicle.

19. The method of forming a protective coating which comprises forming afi h ri containing a vehicle, an acidic plgment, basic pigment and acondensation derivative of rubber which is substantially unoxidized andhardening the film by oxidation of the rubber derivative.

20. An object coated with an oxidized rubber derivative formed by theoxidation of acondensation derivative of rubber in the presence of anacidic pigment and a basic pigment.

21. A coating composition containing a substantially unoxidizedchlorine-containing condensation derivative of rubber which rubberderivative is free from water soluble ingredients formed in theconversion of rubber to such a derivative, is obtainable by quenchingwith water the product of the reaction of chlorostannic acid on rubberin solution and is incorporated in the coating composition in a statesubstantially free from colored impurities.

22. A coating composition, the liquid vehicle of which contains at least50% by Weight of petroleum solvent and the non-volatile portion of whichis composed chiefly of a substantially unoxidized chlorine-containingcondensation derivative of rubber obtainable by quenching with water theproduct of the reaction of chlorostannic acid on rubber in solution.

23. A coating composition which contains at least 20 percent by weightof a substantially unoxidized chlorine-containing condensationderivative of rubber obtainable by quenching with water the product ofthe reaction of chlorostannic acid on rubber in solution.

24. Acoating composition which contains at least 20 percent by weight ofa substantially unoxidized chlorine-containing condensation derivativeof rubber obtainable by quenching with'water the product of the reactionof chlorostannic acid on rubber, in a vehicle composed essentially of apetroleum solvent.

25. A coating composition which comprises a substantially unoxidizedcondensation derivative of rubber which is soluble in petroleum solventand sufficient acidic pigment to render a film of the coatingcomposition resistant to petroleum solvent after 24 hours exposure tolight.

HERBERT A. ENDRES.

